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28.Dd November 13, 2024
29.Dt BUILD 7
30.Os
31.Sh NAME
32.Nm build
33.Nd general instructions on how to build the
34.Fx
35system
36.Sh DESCRIPTION
37The sources for the
38.Fx
39system and its applications are contained in three different directories,
40normally
41.Pa /usr/src ,
42.Pa /usr/doc ,
43and
44.Pa /usr/ports .
45These directories may be initially empty or non-existent until updated with
46Git
47.Po installed from packages with
48.Xr pkg 7
49or from
50.Xr ports 7 Pc .
51Directory
52.Pa /usr/src
53contains the
54.Dq "base system"
55sources, which is loosely defined as the things required to rebuild
56the system to a useful state.
57Directory
58.Pa /usr/doc
59contains the source for the system documentation, excluding the manual
60pages.
61Directory
62.Pa /usr/ports
63contains a tree that provides a consistent interface for building and
64installing third party applications.
65For more information about the ports build process, see
66.Xr ports 7 .
67.Pp
68The
69.Xr make 1
70command is used in each of these directories to build and install the
71things in that directory.
72Issuing the
73.Xr make 1
74command in any directory issues the
75.Xr make 1
76command recursively in all subdirectories.
77With no target specified, the items in the directories are built
78and no further action is taken.
79.Pp
80A source tree is allowed to be read-only.
81As described in
82.Xr make 1 ,
83objects are usually built in a separate object directory hierarchy
84specified by the environment variable
85.Va MAKEOBJDIRPREFIX ,
86or under
87.Pa /usr/obj
88if variable
89.Va MAKEOBJDIRPREFIX
90is not set.
91The canonical object directory is described in the documentation for the
92.Cm buildworld
93target below.
94.Pp
95The build may be controlled by defining
96.Xr make 1
97variables described in the
98.Sx ENVIRONMENT
99section below, and by the variables documented in
100.Xr make.conf 5 .
101.Pp
102The default components included in the build are specified in the file
103.Pa /etc/src.conf
104in the source tree.
105To override the default file, include the SRCCONF option in the make steps,
106pointing to a custom src.conf file.
107For more information see
108.Xr src.conf 5 .
109.Pp
110The following list provides the names and actions for the targets
111supported by the build system:
112.Bl -tag -width ".Cm cleandepend"
113.It Cm analyze
114Run Clang static analyzer against all objects and present output on stdout.
115.It Cm check
116Run tests for a given subdirectory.
117The default directory used is
118.Pa ${.OBJDIR} ,
119but the check directory can be changed with
120.Pa ${CHECKDIR} .
121.It Cm checkworld
122Run the
123.Fx
124test suite on installed world.
125.It Cm clean
126Remove any files created during the build process.
127.It Cm cleandepend
128Remove the
129.Pa ${.OBJDIR}/${DEPENDFILE}*
130files generated by prior
131.Dq Li "make"
132and
133.Dq Li "make depend"
134steps.
135.It Cm cleandir
136Remove the canonical object directory if it exists, or perform
137actions equivalent to
138.Dq Li "make clean cleandepend"
139if it does not.
140This target will also remove an
141.Pa obj
142link in
143.Pa ${.CURDIR}
144if that exists.
145.Pp
146It is advisable to run
147.Dq Li "make cleandir"
148twice: the first invocation will remove the canonical object directory
149and the second one will clean up
150.Pa ${.CURDIR} .
151.It Cm depend
152Generate a list of build dependencies in file
153.Pa ${.OBJDIR}/${DEPENDFILE} .
154Per-object dependencies are generated at build time and stored in
155.Pa ${.OBJDIR}/${DEPENDFILE}.${OBJ} .
156.It Cm install
157Install the results of the build to the appropriate location in the
158installation directory hierarchy specified in variable
159.Va DESTDIR .
160.It Cm obj
161Create the canonical object directory associated with the current
162directory.
163.It Cm objlink
164Create a symbolic link to the canonical object directory in
165.Pa ${.CURDIR} .
166.It Cm tags
167Generate a tags file using the program specified in the
168.Xr make 1
169variable
170.Va CTAGS .
171The build system supports
172.Xr ctags 1
173and
174.Nm "GNU Global" .
175.El
176.Pp
177The other supported targets under directory
178.Pa /usr/src
179are:
180.Bl -tag -width ".Cm distributeworld"
181.It Cm buildenv
182Spawn an interactive shell with environment variables set up for
183building the system or individual components.
184For cross-building the target architecture needs to be specified with
185.Xr make 1
186variables
187.Va TARGET_ARCH
188and
189.Va TARGET .
190.Pp
191This target is only useful after a complete toolchain (including
192the compiler, linker, assembler, headers and libraries) has been
193built; see the
194.Cm toolchain
195target below.
196.It Cm buildworld
197Build everything but the kernel, configure files in
198.Pa etc ,
199and
200.Pa release .
201The object directory can be changed from the default
202.Pa /usr/obj
203by setting the
204.Pa MAKEOBJDIRPREFIX
205.Xr make 1
206variable.
207The actual build location prefix used
208depends on the
209.Va WITH_UNIFIED_OBJDIR
210option from
211.Xr src.conf 5 .
212If enabled it is
213.Pa ${MAKEOBJDIRPREFIX}${.CURDIR}/${TARGET}.${TARGET_ARCH}
214for all builds.
215If disabled it is
216.Pa ${MAKEOBJDIRPREFIX}${.CURDIR}
217for native builds, and
218.Pa ${MAKEOBJDIRPREFIX}/${TARGET}.${TARGET_ARCH}${.CURDIR}
219for cross builds and native builds with variable
220.Va CROSS_BUILD_TESTING
221set.
222.It Cm cleankernel
223Attempts to clean up targets built by a preceding
224.Cm buildkernel ,
225or similar step, built from the same source directory and
226.Va KERNCONF .
227.It Cm cleanworld
228Attempt to clean up targets built by a preceding
229.Cm buildworld ,
230or similar step, built from this source directory.
231.It Cm cleanuniverse
232When
233.Va WITH_UNIFIED_OBJDIR
234is enabled, attempt to clean up targets built by a preceding
235.Cm buildworld ,
236.Cm universe ,
237or similar step, for any architecture built from this source directory.
238.It Cm distributeworld
239Distribute everything compiled by a preceding
240.Cm buildworld
241step.
242Files are placed in the directory hierarchy specified by
243.Xr make 1
244variable
245.Va DISTDIR .
246This target is used while building a release; see
247.Xr release 7 .
248.It Cm native-xtools
249This target builds a cross-toolchain for the given
250.Sy TARGET
251and
252.Sy TARGET_ARCH ,
253as well as a select list of static userland tools for the host system.
254This is intended to be used in a jail where QEMU is used to improve
255performance by avoiding emulating binaries that do not need to be emulated.
256.Sy TARGET
257and
258.Sy TARGET_ARCH
259should be defined.
260.It Cm native-xtools-install
261Installs the results to
262.Pa ${DESTDIR}/${NXTP}
263where
264.Va NXTP
265defaults to
266.Pa nxb-bin .
267.Sy TARGET
268and
269.Sy TARGET_ARCH
270must be defined.
271.It Cm packageworld
272Archive the results of
273.Cm distributeworld ,
274placing the results in
275.Va DISTDIR .
276This target is used while building a release; see
277.Xr release 7 .
278.It Cm installworld
279Install everything built by a preceding
280.Cm buildworld
281step into the directory hierarchy pointed to by
282.Xr make 1
283variable
284.Va DESTDIR .
285.Pp
286If installing onto an NFS file system and running
287.Xr make 1
288with the
289.Fl j
290option, make sure that
291.Xr rpc.lockd 8
292is running on both client and server.
293See
294.Xr rc.conf 5
295on how to make it start at boot time.
296.It Cm toolchain
297Create the build toolchain needed to build the rest of the system.
298For cross-architecture builds, this step creates a cross-toolchain.
299.It Cm universe
300For each architecture,
301execute a
302.Cm buildworld
303followed by a
304.Cm buildkernel
305for all kernels for that architecture,
306including
307.Pa LINT .
308This command takes a long time.
309.It Cm kernels
310Like
311.Cm universe
312with
313.Va WITHOUT_WORLDS
314defined so only the kernels for each architecture are built.
315.It Cm worlds
316Like
317.Cm universe
318with
319.Va WITHOUT_KERNELS
320defined so only the worlds for each architecture are built.
321.It Cm targets
322Print a list of supported
323.Va TARGET
324/
325.Va TARGET_ARCH
326pairs for world and kernel targets.
327.It Cm tinderbox
328Execute the same targets as
329.Cm universe .
330In addition print a summary of all failed targets at the end and
331exit with an error if there were any.
332.It Cm toolchains
333Create a build toolchain for each architecture supported by the build system.
334.It Cm xdev
335Builds and installs a cross-toolchain and sysroot for the given
336.Sy TARGET
337and
338.Sy TARGET_ARCH .
339The sysroot contains target library and headers.
340The target is an alias for
341.Cm xdev-build
342and
343.Cm xdev-install .
344The location of the files installed can be controlled with
345.Va DESTDIR .
346The target location in
347.Va DESTDIR
348is
349.Pa ${DESTDIR}/${XDTP}
350where
351.Va XDTP
352defaults to
353.Pa /usr/${XDDIR}
354and
355.Va XDDIR
356defaults to
357.Pa ${TARGET_ARCH}-freebsd .
358.It Cm xdev-build
359Builds for the
360.Cm xdev
361target.
362.It Cm xdev-install
363Installs the files for the
364.Cm xdev
365target.
366.It Cm xdev-links
367Installs autoconf-style symlinks to
368.Pa ${DESTDIR}/usr/bin
369pointing into the xdev toolchain in
370.Pa ${DESTDIR}/${XDTP} .
371.El
372.Pp
373Kernel specific build targets in
374.Pa /usr/src
375are:
376.Bl -tag -width ".Cm distributekernel"
377.It Cm buildkernel
378Rebuild the kernel and the kernel modules.
379The object directory can be changed from the default
380.Pa /usr/obj
381by setting the
382.Pa MAKEOBJDIRPREFIX
383.Xr make 1
384variable.
385.It Cm installkernel
386Install the kernel and the kernel modules to directory
387.Pa ${DESTDIR}/boot/kernel ,
388renaming any pre-existing directory with this name to
389.Pa kernel.old
390if it contained the currently running kernel.
391The target directory under
392.Pa ${DESTDIR}
393may be modified using the
394.Va INSTKERNNAME
395and
396.Va KODIR
397.Xr make 1
398variables.
399.It Cm distributekernel
400Install the kernel to the directory
401.Pa ${DISTDIR}/kernel/boot/kernel .
402This target is used while building a release; see
403.Xr release 7 .
404.It Cm packages
405Create a
406.Xr pkg 7
407repository containing packages that can be used to create or upgrade an
408installation of the base system.
409The output repository is placed in the object directory, under
410.Pa repo/${PKG_ABI}
411where
412.Va PKG_ABI
413is the
414.Xr pkg 7
415ABI for the build target, for example,
416.Pa /usr/obj/${SRCDIR}/repo/FreeBSD:15:amd64 .
417.It Cm packagekernel
418Archive the results of
419.Cm distributekernel ,
420placing the results in
421.Va DISTDIR .
422This target is used while building a release; see
423.Xr release 7 .
424.It Cm kernel
425Equivalent to
426.Cm buildkernel
427followed by
428.Cm installkernel
429.It Cm kernel-toolchain
430Rebuild the tools needed for kernel compilation.
431Use this if you did not do a
432.Cm buildworld
433first.
434.It Cm reinstallkernel
435Reinstall the kernel and the kernel modules, overwriting the contents
436of the target directory.
437As with the
438.Cm installkernel
439target, the target directory can be specified using the
440.Xr make 1
441variable
442.Va INSTKERNNAME .
443.El
444.Pp
445Convenience targets for cleaning up the install destination directory
446denoted by variable
447.Va DESTDIR
448include:
449.Bl -tag -width ".Cm delete-old-libs"
450.It Cm check-old
451Print a list of old files and directories in the system.
452.It Cm delete-old
453Delete obsolete base system files and directories interactively.
454When
455.Li -DBATCH_DELETE_OLD_FILES
456is specified at the command line, the delete operation will be
457non-interactive.
458The variables
459.Va DESTDIR ,
460.Va TARGET_ARCH
461and
462.Va TARGET
463should be set as with
464.Dq Li "make installworld" .
465.It Cm delete-old-libs
466Delete obsolete base system libraries interactively.
467This target should only be used if no third party software uses these
468libraries.
469When
470.Li -DBATCH_DELETE_OLD_FILES
471is specified at the command line, the delete operation will be
472non-interactive.
473The variables
474.Va DESTDIR ,
475.Va TARGET_ARCH
476and
477.Va TARGET
478should be set as with
479.Dq Li "make installworld" .
480.El
481.Sh ENVIRONMENT
482Variables that influence all builds include:
483.Bl -tag -width ".Va MAKEOBJDIRPREFIX"
484.It Va DEBUG_FLAGS
485Defines a set of debugging flags that will be used to build all userland
486binaries under
487.Pa /usr/src .
488When
489.Va DEBUG_FLAGS
490is defined, the
491.Cm install
492and
493.Cm installworld
494targets install binaries from the current
495.Va MAKEOBJDIRPREFIX
496without stripping,
497so that debugging information is retained in the installed binaries.
498.It Va DESTDIR
499The directory hierarchy prefix where built objects will be installed.
500If not set,
501.Va DESTDIR
502defaults to the empty string.
503If set,
504.Va DESTDIR
505must specify an absolute path.
506.It Va MAKEOBJDIRPREFIX
507Defines the prefix for directory names in the tree of built objects.
508Defaults to
509.Pa /usr/obj
510if not defined.
511This variable should only be set in the environment or
512.Pa /etc/src-env.conf
513and not via
514.Pa /etc/make.conf
515or
516.Pa /etc/src.conf
517or the command line.
518.Va MAKEOBJDIRPREFIX
519must specify an absolute path.
520.It Va WITHOUT_WERROR
521If defined, compiler warnings will not cause the build to halt,
522even if the makefile says otherwise.
523.It Va WITH_CTF
524If defined, the build process will run the DTrace CTF conversion
525tools on built objects.
526.El
527.Pp
528Additionally, builds in
529.Pa /usr/src
530are influenced by the following
531.Xr make 1
532variables:
533.Bl -tag -width ".Va LOCAL_MODULES_DIR"
534.It Va CROSS_TOOLCHAIN
535Requests use of an external toolchain to build either the world or kernel.
536This value of this variable can either be the full path to a file,
537or the base name of a file in
538.Pa ${LOCALBASE}/share/toolchains .
539The file should be a make file which sets variables to request an external
540toolchain such as
541.Va XCC .
542.Pp
543External toolchains are available in ports for both LLVM and GCC/binutils.
544For external toolchains available in ports,
545.Va CROSS_TOOLCHAIN
546should be set to the name of the package.
547LLVM toolchain packages use the name llvm<major version>.
548GCC toolchains provide separate packages for each architecture and use the
549name ${MACHINE_ARCH}-gcc<major version>.
550.It Va KERNCONF
551Overrides which kernel to build and install for the various kernel
552make targets.
553It defaults to
554.Cm GENERIC .
555.It Va KERNCONFDIR
556Overrides the directory in which
557.Va KERNCONF
558and any files included by
559.Va KERNCONF
560should be found.
561Defaults to
562.Pa sys/${ARCH}/conf .
563.It Va KERNFAST
564If set, the build target
565.Cm buildkernel
566defaults to setting
567.Va NO_KERNELCLEAN ,
568.Va NO_KERNELCONFIG ,
569and
570.Va NO_KERNELOBJ .
571When set to a value other than
572.Cm 1
573then
574.Va KERNCONF
575is set to the value of
576.Va KERNFAST .
577.It Va LOCAL_DIRS
578If set, this variable supplies a list of additional directories relative to
579the root of the source tree to build as part of the
580.Cm everything
581target.
582The directories are built in parallel with each other,
583and with the base system directories.
584Insert a
585.Va .WAIT
586directive at the beginning of the
587.Va LOCAL_DIRS
588list to ensure all base system directories are built first.
589.Va .WAIT
590may also be used as needed elsewhere within the list.
591.It Va LOCAL_ITOOLS
592If set, this variable supplies a list of additional tools that are used by the
593.Cm installworld
594and
595.Cm distributeworld
596targets.
597.It Va LOCAL_LIB_DIRS
598If set, this variable supplies a list of additional directories relative to
599the root of the source tree to build as part of the
600.Cm libraries
601target.
602The directories are built in parallel with each other,
603and with the base system libraries.
604Insert a
605.Va .WAIT
606directive at the beginning of the
607.Va LOCAL_DIRS
608list to ensure all base system libraries are built first.
609.Va .WAIT
610may also be used as needed elsewhere within the list.
611.It Va LOCAL_MTREE
612If set, this variable supplies a list of additional mtrees relative to the
613root of the source tree to use as part of the
614.Cm hierarchy
615target.
616.It Va LOCAL_LEGACY_DIRS
617If set, this variable supplies a list of additional directories relative to
618the root of the source tree to build as part of the
619.Cm legacy
620target.
621.It Va LOCAL_BSTOOL_DIRS
622If set, this variable supplies a list of additional directories relative to
623the root of the source tree to build as part of the
624.Cm bootstrap-tools
625target.
626.It Va LOCAL_TOOL_DIRS
627If set, this variable supplies a list of additional directories relative to
628the root of the source tree to build as part of the
629.Cm build-tools
630target.
631.It Va LOCAL_XTOOL_DIRS
632If set, this variable supplies a list of additional directories relative to
633the root of the source tree to build as part of the
634.Cm cross-tools
635target.
636.It Va PORTS_MODULES
637A list of ports with kernel modules that should be built and installed
638as part of the
639.Cm buildkernel
640and
641.Cm installkernel
642process.
643.Bd -literal -offset indent
644make PORTS_MODULES=emulators/virtualbox-ose-kmod kernel
645.Ed
646.It Va LOCAL_MODULES
647A list of external kernel modules that should be built and installed
648as part of the
649.Cm buildkernel
650and
651.Cm installkernel
652process.
653Defaults to the list of sub-directories of
654.Va LOCAL_MODULES_DIR .
655.It Va LOCAL_MODULES_DIR
656The directory in which to search for the kernel modules specified by
657.Va LOCAL_MODULES .
658Each kernel module should consist of a directory containing a makefile.
659Defaults to
660.Pa ${LOCALBASE}/sys/modules .
661.It Va SRCCONF
662Specify a file to override the default
663.Pa /etc/src.conf .
664The src.conf file controls the components to build.
665See
666.Xr src.conf 5
667.It Va STRIPBIN
668Command to use at install time when stripping binaries.
669Be sure to add any additional tools required to run
670.Va STRIPBIN
671to the
672.Va LOCAL_ITOOLS
673.Xr make 1
674variable before running the
675.Cm distributeworld
676or
677.Cm installworld
678targets.
679See
680.Xr install 1
681for more details.
682.It Va SUBDIR_OVERRIDE
683Override the default list of sub-directories and only build the
684sub-directory named in this variable.
685If combined with
686.Cm buildworld
687then all libraries and includes, and some of the build tools will still build
688as well.
689Specifying
690.Cm -DNO_LIBS ,
691and
692.Cm -DWORLDFAST
693will only build the specified directory as was done historically.
694When combined with
695.Cm buildworld
696it is necessary to override
697.Va LOCAL_LIB_DIRS
698with any custom directories containing libraries.
699This allows building a subset of the system in the same way as
700.Cm buildworld
701does using its sysroot handling.
702This variable can also be useful when debugging failed builds.
703.Bd -literal -offset indent
704make some-target SUBDIR_OVERRIDE=foo/bar
705.Ed
706.It Va SYSDIR
707Specify the location of the kernel source to override the default
708.Pa /usr/src/sys .
709The kernel source is located in the
710.Pa sys
711subdirectory of the source tree checked out from the
712.Pa src.git
713repository.
714.It Va TARGET
715The target hardware platform.
716This is analogous to the
717.Dq Nm uname Fl m
718output.
719This is necessary to cross-build some target architectures.
720For example, cross-building for ARM64 machines requires
721.Va TARGET_ARCH Ns = Ns Li aarch64
722and
723.Va TARGET Ns = Ns Li arm64 .
724If not set,
725.Va TARGET
726defaults to the current hardware platform, unless
727.Va TARGET_ARCH
728is also set, in which case it defaults to the appropriate
729value for that architecture.
730.It Va TARGET_ARCH
731The target machine processor architecture.
732This is analogous to the
733.Dq Nm uname Fl p
734output.
735Set this to cross-build for a different architecture.
736If not set,
737.Va TARGET_ARCH
738defaults to the current machine architecture, unless
739.Va TARGET
740is also set, in which case it defaults to the appropriate
741value for that platform.
742Typically, one only needs to set
743.Va TARGET .
744.El
745.Pp
746Builds under directory
747.Pa /usr/src
748are also influenced by defining one or more of the following symbols,
749using the
750.Fl D
751option of
752.Xr make 1 :
753.Bl -tag -width ".Va LOADER_DEFAULT_INTERP"
754.It Va LOADER_DEFAULT_INTERP
755Defines what interpreter the default loader program will have.
756Valid values include
757.Dq 4th ,
758.Dq lua ,
759and
760.Dq simp .
761This creates the default link for
762.Pa /boot/loader
763to the loader with that interpreter.
764It also determines what interpreter is compiled into
765.Pa userboot .
766.It Va NO_CLEANDIR
767If set, the build targets that clean parts of the object tree use the
768equivalent of
769.Dq make clean
770instead of
771.Dq make cleandir .
772.It Va NO_CLEAN
773If set, no object tree files are cleaned at all.
774This is the default when
775.Va WITH_META_MODE
776is used with
777.Xr filemon 4
778loaded.
779See
780.Xr src.conf 5
781for more details.
782Setting
783.Va NO_CLEAN
784implies
785.Va NO_KERNELCLEAN ,
786so when
787.Va NO_CLEAN
788is set no kernel objects are cleaned either.
789.It Va NO_CTF
790If set, the build process does not run the DTrace CTF conversion tools
791on built objects.
792.It Va NO_SHARE
793If set, the build does not descend into the
794.Pa /usr/src/share
795subdirectory (i.e., manual pages, locale data files, timezone data files and
796other
797.Pa /usr/src/share
798files will not be rebuild from their sources).
799.It Va NO_KERNELCLEAN
800If set, the build process does not run
801.Dq make clean
802as part of the
803.Cm buildkernel
804target.
805.It Va NO_KERNELCONFIG
806If set, the build process does not run
807.Xr config 8
808as part of the
809.Cm buildkernel
810target.
811.It Va NO_KERNELOBJ
812If set, the build process does not run
813.Dq make obj
814as part of the
815.Cm buildkernel
816target.
817.It Va NO_LIBS
818If set, the libraries phase will be skipped.
819.It Va NO_OBJWALK
820If set, no object directories will be created.
821This should only be used if object directories were created in a
822previous build and no new directories are connected.
823.It Va UNIVERSE_TOOLCHAIN
824Requests use of the toolchain built as part of the
825.Cm universe
826target as an external toolchain.
827.It Va WORLDFAST
828If set, the build target
829.Cm buildworld
830defaults to setting
831.Va NO_CLEAN ,
832.Va NO_OBJWALK ,
833and will skip most bootstrap phases.
834It will only bootstrap libraries and build all of userland.
835This option should be used only when it is known that none of the bootstrap
836needs changed and that no new directories have been connected to the build.
837.El
838.Pp
839Builds under directory
840.Pa /usr/doc
841are influenced by the following
842.Xr make 1
843variables:
844.Bl -tag -width ".Va DOC_LANG"
845.It Va DOC_LANG
846If set, restricts the documentation build to the language subdirectories
847specified as its content.
848The default action is to build documentation for all languages.
849.El
850.Pp
851Builds using the
852.Cm universe
853and related targets are influenced by the following
854.Xr make 1
855variables:
856.Bl -tag -width ".Va USE_GCC_TOOLCHAINS"
857.It Va JFLAG
858Pass the value of this variable to each
859.Xr make 1
860invocation used to build worlds and kernels.
861This can be used to enable multiple jobs within a single architecture's build
862while still building each architecture serially.
863.It Va MAKE_JUST_KERNELS
864Only build kernels for each supported architecture.
865.It Va MAKE_JUST_WORLDS
866Only build worlds for each supported architecture.
867.It Va WITHOUT_WORLDS
868Only build kernels for each supported architecture.
869.It Va WITHOUT_KERNELS
870Only build worlds for each supported architecture.
871.It Va UNIVERSE_TARGET
872Execute the specified
873.Xr make 1
874target for each supported architecture instead of the default action of
875building a world and one or more kernels.
876This variable implies
877.Va WITHOUT_KERNELS .
878.It Va USE_GCC_TOOLCHAINS
879Use external GCC toolchains to build the requested targets.
880If the required toolchain package for a supported architecture is not installed,
881the build for that architecture is skipped.
882.It Va TARGETS
883Only build the listed targets instead of each supported architecture.
884.It Va EXTRA_TARGETS
885In addition to the supported architectures, build the semi-supported
886architectures.
887A semi-supported architecture has build support in the
888.Fx
889tree, but receives significantly less testing and is generally for
890fringe uses that do not have a wide appeal.
891.El
892.Sh FILES
893.Bl -tag -width ".Pa /usr/share/examples/etc/make.conf" -compact
894.It Pa /usr/doc/Makefile
895.It Pa /usr/doc/share/mk/doc.project.mk
896.It Pa /usr/ports/Mk/bsd.port.mk
897.It Pa /usr/ports/Mk/bsd.sites.mk
898.It Pa /usr/share/examples/etc/make.conf
899.It Pa /usr/src/Makefile
900.It Pa /usr/src/Makefile.inc1
901.El
902.Sh EXAMPLES
903For an
904.Dq approved
905method of updating your system from the latest sources, please see the
906.Sx COMMON ITEMS
907section in
908.Pa src/UPDATING .
909.Pp
910The following sequence of commands can be used to cross-build the system for
911the arm64 (aarch64) architecture on a different host architecture, such as
912amd64:
913.Bd -literal -offset indent
914cd /usr/src
915make TARGET=arm64 buildworld buildkernel
916make TARGET=arm64 DESTDIR=/clients/arm64 installworld installkernel
917.Ed
918.Sh SEE ALSO
919.Xr cc 1 ,
920.Xr install 1 ,
921.Xr make 1 ,
922.Xr make.conf 5 ,
923.Xr src.conf 5 ,
924.Xr arch 7 ,
925.Xr development 7 ,
926.Xr pkg 7 ,
927.Xr ports 7 ,
928.Xr release 7 ,
929.Xr tests 7 ,
930.Xr config 8 ,
931.Xr etcupdate 8 ,
932.Xr reboot 8 ,
933.Xr shutdown 8
934.Sh HISTORY
935The
936.Nm
937manpage first appeared in
938.Fx 4.3 .
939.Sh AUTHORS
940.An Mike W. Meyer Aq Mt mwm@mired.org
941